This invention relates to a novel method of preparing carboxylic acids and particularly to the preparation of carboxylic acids from acylhydroximyl halides.
Carboxylic acids can be prepared by contacting nitroketones with aqueous sodium hydroxide or refluxing in sodium acetate. This method requires isolation of the intermediate sodium carboxylate and acidification to convert the intermediate to the acid. In another method involving the refluxing of nitroketones in aqueous ammonium hydroxide, there results a mixture of carboxylic acids and amides. U.S. Pat. No. 3,415,856 describes a method of preparing carboxylic acids by contacting a nitroketone with water in the presence of an acid, such as the mineral acid, a hydrocarbon sulfonic acid or a haloacetic acid and where the method produces two distinct carboxylic acids. While yields of 60 and 70 mole percent of monocarboxylic acids are indicated as provided by the method, there still remains substantial room for improvement. We have now found a method whereby individual carboxylic acids can be produced, which method also provides as a valuable coproduct an ammonium halide.
It is therefore an object of this invention to provide a method for the preparation of carboxylic acids in high yields.
Another object of this invention is to provide a method for the preparation of carboxylic acids from acylhydroximyl halides.
Yet another object of this invention is to provide a method for converting acylhydroximyl halides to a carboxylic acid and an ammonium halide.
Other objects and advantages will become apparent from a reading of the following detailed description and examples.